Solar panels/charge controller and RFI

I would try giving frank a call at bz products.  He may have a solution for you.  Other brands of charge controllers often advertise low emi emissions that meet or exceed FCC part 15 EMI emissions requirements.  If no solution is found, we can  help you find something that may cause less itnerference if need be.  the number for bz products is 314-644-2490.

james - Alt-E staff

Hi Jim - I would recommend that you try to determine if the RFI is radiated or conducted. In other words, is the noise coming over the power lines into the radio (conducted) or over the air (radiated). This is made somewhat difficult in that the noise may actually be travelling on the ground system (and could come in on the shield of your coax into the radio).  But you could try running the radio off a stand-alone battery for the test. If the noise is gone or greatly reduced, it is conducted and you should be able to control it with adequate common mode and differential mode filtering (including commercial filters for this purpose). If there is no improvement it is radiated, and things like shielding the controller, or increased separation between the controller and the radio system (esp. the antenna) can be tried (I'd try that first before attempting shielding because building an adequate shield is not as easy as it sounds).

As a general note, even equipment that meet FCC EMI/RFI levels can still wreak havoc with sensitive AM/SSB radio equipment.  So when the manufacturer says it passes FCC Part 15, it doesn't solve your problem.

By the way, one of the worst offenders of the RF spectrum (when using AM or SSB) is the CFL running from 12vdc. If you have any of those, disconnect them to see what they contribute to your problem.  I found they make AM/SSB operation impossible when located within 50' of the antenna system.

Best Regards,

Tom Hardy, PE
HVTA, Inc.

I installed two KC130 panels in series with the BZ Products MPPT250 charge controller on our Airstream supplying two Deka 8G24 gel batteries.  I am pleased with the results so far.  On a recent day I tested the controller as directed by Frank at BZ Products (I drew the batteries down by leaving the lights on overnight).  Bypassing the controller the charging rate was 4 amps (PV line disconnected and touched to the output battery terminal); reconnecting the PV line to its terminal produced a 9.4 amp charge.

I am interested in whether the original poster, Jim Smiley, resolved his interference problem with his HF SSB radio.  I also operate HF amateur radio equipment although typically sitting outside the trailer.  I had not noticed any interference with my radio, a Yaesu FT-897, outside about 15 feet away but powered by the trailer batteries. I intend to run coax into the trailer so that I can operate from inside during bad weather so I may have the same problem.